heli coil

[docjeffry]

I need to replace my upper (thank God) in cylinder #3 of a Lycoming o-235-C2C. In reviewing the FAA's maintenance manual, vol. 1, CH 5, I noted an absence of and type of adhesive such as locktite, etc. Any comments on that? Note: All of my owner assist MX is performed with a certified A&P/AI. 

 

I'll let you know how I do.

[Pinecone]

On 3/24/2021 at 5:57 PM, M20Doc said:

If you’ve ever seen this stuff, you must be older than you let on.

Clarence

The USAF still used it into the 80s.  They even ran the O-2A/Bs (Cessna Skymaster) on it.  I am sure they had lead fouling issues.

You cannot have an "octane rating" higher than 100, as by definition, pure iso-octane is 100 octane.   So above that it is technically a performance number.

To get those higher ratings, you go to aromatic compounds.  I know that at one point, Formula 1 cars were running almost pure toluene.  Xylene is used in G100UL to boost the rating.  And metallic additives, such as tetraethyl lead.

Even today, you can get leaded race fuels.  VP Racing fuels makes an MON 120+ fuel.  MON is similar to the 115 of the 115/145 fuel.

IIRC G100UL is something like 98/140+

 

 

 

[PT20J]

7 hours ago, docjeffry said:

I need to replace my upper (thank God) in cylinder #3 of a Lycoming o-235-C2C. In reviewing the FAA's maintenance manual, vol. 1, CH 5, I noted an absence of and type of adhesive such as locktite, etc. Any comments on that? Note: All of my owner assist MX is performed with a certified A&P/AI. 

 

I'll let you know how I do.

If you are talking about the spark plug, Lycoming uses a special serrated helicoil to make sure it stays in place. There is a special tool to do it correctly.

https://www.aircraft-tool.com/shop/detail.aspx?id=4260-18